描述了炔基(苯基)碘化甲苯磺酸盐与全氟烷烃亚磺酸钠(R fn SO 2 Na)的无添加剂和过渡金属的全氟烷烃磺酰化。亲核性差的R fn SO 2 Na与二氯甲烷中的炔基(苯基)碘鎓盐在室温下在氮气氛下反应5-60分钟,从而以令人满意的定量收率提供了各种炔属三氟甲酮和炔基全氟烷基砜。碘鎓盐中芳基乙炔基部分的苯环上取代基的位置对反应有很大影响。五元环乙烯基砜的形成表明该反应通过亚烷基卡宾中间体。此外,成功扩大反应规模也证明了该新方法的实用性。该方法的优点包括反应时间短,条件温和以及易于获得全氟链烷磺酰化试剂(R fn SO 2 Na)。
alkynylperfluoroalkanesulfones 5a–e have been prepared and their cycloaddition reactivity towards dienes and diazomsthane has been studied. The faster reaction rate of 5b with cyclopentadiene than 5a and vice versa with tetracyclone (6) has been explained on steric and electronic affects. The alkynylperfluoroalkanesulfones are very reactive towards nucleophilic additions. Attempts to prepare the highly reactive bis-perfluoroalkane-
Radical 1,2,3-tricarbofunctionalization of α-vinyl-β-ketoesters enabled by a carbon shift from an all-carbon quaternary center
作者:Qi Zhang、Mong-Feng Chiou、Changqing Ye、Xiaobin Yuan、Yajun Li、Hongli Bao
DOI:10.1039/d2sc00902a
日期:——
enables further C–Cbondformation on the tertiary carbon intermediate with the aim of reconstructing a new all-carbon quaternary center. The good functional group compatibility ensures diverse synthetic transformations of this method. Experimental and theoretical studies reveal that the excellent diastereoselectivity should be attributed to the hydrogen bonding between the substrates and solvent.